1. Field of the Invention
The present invention relates to an array substrate of a fringe field switching (FFS) mode liquid crystal display (LCD) panel and method of manufacturing the same, and more particularly, to an array substrate of an FFS mode LCD panel and method of manufacturing the same in which the gate electrodes, the gate lines and the common electrode are disposed on the same layer and patterned by the same photolithographic process.
2. Description of the Prior Art
Liquid crystal display panels, based on different directions of applied electric field that drives the liquid crystal, may be broadly classified into vertical electric field type LCD panels and horizontal electric field type LCD panels.
In a horizontal electric field type LCD panel, the liquid crystal molecules sealed within are driven by a horizontal electric field formed between a common electrode and a pixel electrode. Due to the common electrode and the pixel electrode arranged in parallel on the same plane of the lower substrate, the liquid crystal is able to be driven by the horizontal electric field generated between the common electrode and the pixel electrode. Therefore, the horizontal electric field type LCD panel is also known as an in-plane switching (hereinafter, referred to as “IPS”) mode LCD. The IPS mode LCD panel has an advantage of wider viewing angle, but often accompanied with a disadvantage in that the aperture ratio and transmittance are relatively low.
In order to improve the aperture ratio and transmittance of the IPS mode LCD panel, there has been proposed a fringe field switching (FFS) mode LCD panel wherein the liquid crystal molecules are driven by a fringe electric field formed between a common electrode and a pixel electrode in which the pixel electrode is either disposed over the common electrode on the lower substrate or arranged below the common electrode on the lower substrate. Either one of the common electrode or the pixel electrode includes a plurality of slits and stripe electrodes so that the fringe electric field is generated thereto.
In an FFS mode LCD panel, the common electrode and the pixel electrode formed on the lower substrate are both made of a transparent conducting material such as indium tin oxide (ITO), and a distance between the common electrode and the pixel electrode is smaller than a distance between the upper and lower substrates. In addition, either the common electrode or the pixel electrode would have a sufficient width so that the liquid crystal molecules above the pixel electrode and the common electrode can be all driven. Since the pixel electrode and the common electrode are both made of transparent conducting material which is light permeable, the FFS mode LCD panel obtains an improved aperture ratio and transmittance over the IPS mode LCD panel.
There has been a proposed method of manufacturing an FFS mode LCD panel, which requires six photolithographic processes to form the array substrate of the FFS mode LCD panel. However, this conventional method suffers from high manufacturing complexity and high cost.